|Publication number||US4020457 A|
|Application number||US 05/615,679|
|Publication date||Apr 26, 1977|
|Filing date||Sep 22, 1975|
|Priority date||Sep 27, 1974|
|Also published as||CA1060944A1, DE2446171A1|
|Publication number||05615679, 615679, US 4020457 A, US 4020457A, US-A-4020457, US4020457 A, US4020457A|
|Original Assignee||Daimler-Benz Aktiengesellschaft|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (2), Referenced by (2), Classifications (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention relates to an installation for increasing the brightness differences in combined lights, preferably in blinker and position light of motor vehicles, in which a first and a second light are adapted to be connected to energizing voltage separately and are arranged or mounted in a common housing or in direct proximity to one another.
In motor vehicles, combined lights of the aforementioned type are frequently used, and they generally consist either of individual lamps in a common housing or of two-filament lamps. With such lights, the respective switched-on and switched off condition of the lamp cannot always be recognized unequivocally because of the influence which one lamp has on the other. Thus, for example, with a combination blinker-position light which is constructed as a two-filament lamp of, for example, 5 Watts for the position light and 20 Watts for the blinker light, the recognizability of the blinker signal is impaired by the already existing background brightness provided by the position lamp.
The present invention is concerned with the task of avoiding the described disadvantages of the prior art. Consequently, an installation is proposed, according to which both lights are recognized unequivocally and do not influence one another and interfere with one another. The underlying problems are solved according to the present invention in the installations of the aforementioned type in that the first light is adapted to be automatically turned off when turning on the second light, and in that the first light is adapted to be automatically turned on again when the second light is turned off. In detail, it is then proposed according to the present invention that a switching relay which opens when energized, is connected into the energizing circuit of the first light, whereby the energizing circuit of the switching relay is connected in parallel to the second light.
The proposed installation offers the advantage that each lamp can be unequivocally recognized by itself so that the turned-on condition of both lamps is defined clearly even for the more distant observer. The "outshining effect" which occurred heretofore, is therefore avoided in an advantageous manner by the proposal in accordance with the present invention.
It has already been mentioned that the present invention is preferably applicable with particular advantage, when a turn indicator or blinker light and a position or width-indicating light is involved. For this case, namely, with a blinker light as the second light, which light is switched on by the turn indicator or blinker unit, the present invention proposes that a normally closed time-delay relay that opens when energized be connected in the energizing circuit, and that the releasing-time-constant of the time-delay relay be greater than the dark period of the turn indicator or blinker unit. A further feature of the present invention thereby resides in the fact that the energizing circuit is adapted to be controlled by means of a transistor adapted to be rendered conductive, to the base of which are connected a time-constant circuit, formed by a resistance and condenser, and a blocking diode of the flasher or blinker unit.
Accordingly, it is an object of the present invention to provide an installation for increasing the brightness differences in combined lights, especially of blinker and position lights in motor vehicles, which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.
Another object of the present invention resides in an installation for increasing the brightness differences in combined lights which assures an unequivocal individual recognition of the two lights.
A further object of the present invention resides in an installation of the type described above in which the two lights do not mutually interfere with one another so that the recognizability of the blinker signal is not impaired by the already prevailing background brightness of the position light.
Still another object of the present invention resides in a system for increasing the brightness differences in combined lights so that the turned-on condition of each of the two lamps can be clearly defined also for distant observers.
These and other objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawing which shows, for purposes of illustration only, two embodiments in accordance with the present invention, and wherein:
FIG. 1 is a schematic circuit diagram illustrating the principle of a circuit in accordance with the present invention for an installation to increase the brightness of combined lights; and
FIG. 2 is a schematic circuit diagram of a blinker circuit in accordance with the present invention.
Referring now to the drawing wherein like reference characters are used throughout the two views to designate like parts, reference will be made in the following text to individual lights or lamps. However, corresponding to the explanation hereinabove, the principle according to the present invention is also applicable to two-filament lamps, whence reference to lights or lamps in the following description is intended to include analogously the concept of "filaments" instead of "separate lamps."
According to FIG. 1, a first lamp L1 is adapted to be switched on and off by way of a first switch S1 and a second lamp L2 is adapted to be switched on and off by way of a second switch S2. The lamp L.sub. 2 is designed to be brighter than the lamp L1, for example. The contact of a normally closed switching relay SR is connected in the energizing circuit of the first lamp L1 in series with the switch S1 ; the contact of the switching relay SR is thereby closed in the de-energized condition. The energizing circuit E of the switching relay SR is connected in parallel to the lamp L2, i.e., it is also turned on by way of the switch S2.
If in the illustrated circuit the switch S1 is actuated, then the lamp L1 lights up. If now in this switched-on condition of the lamp L1, the switch S2 for the lamp L2 is actuated, then the lamp L2 lights up and simultaneously the switching relay SR is energized by way of the energizing circuit E and attracts its armature. As a result thereof, the switch or contact at the switching relay SR opens and the lamp L1 extinguishes. This extinction lasts until the switch S2 is again opened and the lamp L2 is turned off. The lamp L1 is then automatically energized again, i.e., supplied with current, since the switching relay SR now closes again. Of course, if the switch S1 should have been opened in the meantime, then the lamp L1 also continues to remain dark.
According to FIG. 2, the lamp L1 is the position or width-indicating light of a motor vehicle which together with the blinker or turn-indicator lamp L2 is accommodated in a common housing. The basic circuit is functionally the same as the circuit of FIG. 1 whereby, however, the two switches S1 and S2 have been omitted for the sake of clarity. The switching relay SR is again connected in the energizing circuit E which in this case is controlled by way of a transistor T. The blinker pulses B obtained by conventional means are fed by way of a current-limiting resistance R1, a blocking diode D and a time-constant circuit Z to the base of the transistor T which is rendered conductive and therewith causes the switching relay SR to attract its armature. As a result thereof, the lamp L1 is turned off. The time-constant Z, which consists of the condenser C and of the resistance R2, is so selected that its decay-time is greater than the dark period of the flasher or blinker unit. Consequently, during this dark period, the condenser C is discharged at a slow rate so that the transistor T remains conductive. Only when the flasher or blinker unit is turned off and the blinker pulses B disappear, will the relay SR again drop off and the lamp L1 again light up.
While I have shown and described only two embodiments in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US2321803 *||Aug 2, 1940||Jun 15, 1943||Gen Motors Corp||Direction signal circuit|
|US3896415 *||Jul 6, 1973||Jul 22, 1975||Carter Iii Adolphus J||Signal light circuit integrator|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4835406 *||Jan 29, 1987||May 30, 1989||Roenndahl Sylve||Switching device|
|DE3214095A1 *||Apr 16, 1982||Oct 20, 1983||Vaclav Dipl Ing Cevela||Hazard warning system with travel direction change indicator|
|U.S. Classification||340/468, 340/475|